Group of EightˌGroup of ˈEight abbreviation G8 nounECONOMICSORGANIZATIONS the countries with the eight largest economies: Britain, Canada, France, Germany, Italy, Japan, the US, and Russia. Their finance ministers meet regularly to discuss economic and financial subjects that affect them and other countriesThe G8 agenda now includes a wide range of foreign affairs and international issues, such as terrorism, nuclear safety, the environment, UN reform and development assistance.